1. Field of the Invention
The present invention relates to an apparatus and to a method to at least partially rotate continuous tubing in order to control rotational positioning of concentric tubing.
2. Prior Art
The oil and gas drilling, production, and service industries often make use of tubing in a concentric configuration with a first tube inside of a larger tube. In the past, downhole tubing was typically assembled from a series of lengths or sections, commonly called “joints,” joined together at the ends. The sections would be connected on installation downhole and then unconnected on retrieval. More recently, continuous tubing has been introduced. Continuous tubing may be fabricated from carbon steel or other material. The continuous tubing may be manufactured in a number of ways including by welding a continuous flat strip into a tube. The tubing diameter typically ranges from less than an inch up to four inches. Tube lengths in excess of 30,000 feet have been manufactured.
Coiled tubing and its associated equipment provide a relatively small foot print and short rig-up and rig-down times. In addition, it provides for faster movement in and out of the well, called “trips.”
The continuous length of concentric tubing is stored wound on a spool or reel. The concentric tubing is later straightened prior to entering the well bore. In order to install, the larger diameter tubing is installed or run down in the bore from the surface downhole. Thereafter, the inner tubing is installed or run down inside and concentric to the larger diameter outer tubing.
Rotation and partial turning of such tubing is often required during drilling, during oil or gas production or during service operations. Rotation or turning the tubing that extends down in a vertical, directional, or horizontal well or bore has heretofor been accomplished by either turning the tubing at the surface or by utilizing a downhole motor.
If the tubing is coiled or continuous tubing on a spool, it cannot be easily rotated or turned from the surface without rotating the entire spool. In these situations, a downhole motor may be required.
The present invention has many applications. Turning or orienting such a tube downhole is important when the tubing or tube is connected to a tool in a bore downhole in the earth, such as for a drill bit on the end of the tubing, and that tool needs to be turned or partially rotated. Another example is when a tool needs to be oriented in a particular direction, such as for control of a downhole directional instrument or tool, such as a “whipstock.”
Also, a short rotation of the coiled tube combined with a vertical, axial movement allows attachment, release and/ or sealing of a separate tube or tool. One type of tool is commonly known as a “J” slot type connection, which is well known in the industry. In particular, directional or horizontal drilling requires such specific movement of downhole tools. Such downhole tools can be drill bits, and drill motors attached to directional kick-off tools, bent pipe, measurement instruments, or even a given orientation line on the downhole tubing.
Continuous coiled tubing is spooled and re-spooled on to a reel. Continuous coiled tubing is normally stored on a reel or spool for transportation and storage at the surface. In order to install, the tubing is unwound off of a reel at the surface and passed over a guide arch or gooseneck their straightened and then directed downhole. An injector head provides the motive force to run the tubing downhole. The reverse operation is performed to retrieve the tubing.
The present invention, thus, also provides a means or mechanism for rotating, turning or orienting the tubing that may be helpful in spreading out the stresses encountered in the multiple uncoiling and recoiling processes, thereby extending the useful life of the continuous tubing.